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Busstom Samba Member
Joined: November 23, 2014 Posts: 3841 Location: San Jose, CA
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Posted: Thu May 18, 2017 7:44 pm Post subject: Another VW Engineering Blunder... |
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…or a rational explanation?
A quick search didn’t turn up anything, but I’m surely not the first person to notice this. Why did VW cant the shock mounting boss out of plane with the upper mounting bolt, and way out of perpendicularity to the swinging arc of the bearing housing? There's roughly an 8 - 10 degree disparity between the upper and lower bolt planes.
This flies in the face of sound engineering principles, and in my case, not only are the bushings and sleeves wallowed out on my lower shock mounts, but the bolts are slightly bent.
Does anyone know why VW designed these like this? It's very odd. Not to mention, annoying.
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air-h2o-air Samba Member
Joined: January 25, 2015 Posts: 579
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Posted: Thu May 18, 2017 7:57 pm Post subject: Re: Another VW Engineering Blunder... |
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annoying? why so? many shocks on many different vehicles do not have parallel mounting points |
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Abscate Samba Member
Joined: October 05, 2014 Posts: 22641 Location: NYC/Upstate/ROW
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Posted: Thu May 18, 2017 8:31 pm Post subject: Re: Another VW Engineering Blunder... |
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Has anyone swagged the force on the shock bolt? It might be lower than people think.
The shock is the damper, not the spring resisting the force. _________________ .ssS! |
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Busstom Samba Member
Joined: November 23, 2014 Posts: 3841 Location: San Jose, CA
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Posted: Thu May 18, 2017 10:44 pm Post subject: Re: Another VW Engineering Blunder... |
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Abscate wrote: |
Has anyone swagged the force on the shock bolt? It might be lower than people think.
The shock is the damper, not the spring resisting the force. |
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That's true. But also, the valving in the shock absorber itself produces resistance in order to do it's job. So, for example, while happily motoring along a smooth stretch of freeway, the shock absorber is deviating very little from it's state of equilibrium, and the bolts see almost no force; but during that very instant that the wheel drops into a pothole at freeway speed and then pops back out (compresses), the result is a rapid acceleration against the shock absorber and, for an instant, produces a shit ton of force on the bolts, certainly in the thousands of g's.
I know, I know, it's a dynamic relationship: the greater the torsion bar twists and resistance increases, the load on the bolts drops off rapidly.
Rocking a rigid metal rule against my bent shock bolts, I'd estimate that they're tweaked about .010" or so. Sure, it's not much, but enough that one of them doesn't slide all the way into the boss anymore. I suspect it's a result of the bolts having to exist in a "wedged" state, so that once the lower bolt(s) is levered into the mounting boss, the bolt no longer benefits from uniform cushioning around the diameter of the rubber mount bushing, and the cumulative effects over time just tweak the bolts.
Just sayin'. |
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lil-jinx Samba Member
Joined: August 14, 2013 Posts: 1109 Location: New Brunswick,Canada
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Posted: Fri May 19, 2017 3:13 am Post subject: Re: Another VW Engineering Blunder... |
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If the shock or the bearing housing is worn out of round,that means the shock bolt was not tight at some point and allowed the shock to pound on the bolt.If all was tight there would be no movement,therefor no wear. _________________ https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy
1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes. |
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lil-jinx Samba Member
Joined: August 14, 2013 Posts: 1109 Location: New Brunswick,Canada
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Posted: Fri May 19, 2017 3:14 am Post subject: Re: Another VW Engineering Blunder... |
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If the shock or the bearing housing is worn out of round,that means the shock bolt was not tight at some point and allowed the shock to pound on the bolt.If all was tight there would be no movement,therefor no wear.
I went and took a look at my shock mount bolts,the top bolt is also on an angle that looks the same as the bottom bolt,when the shock is installed at ride height it is angled in at the top which explains the bolts been on an angle.I did not measure the angles to see if they are the same,I assume they are,as you said it makes no sense to have them different. _________________ https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy
1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes.
Last edited by lil-jinx on Fri May 19, 2017 4:17 am; edited 1 time in total |
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madmike Samba Member
Joined: July 11, 2005 Posts: 5292 Location: Atlanta,Michigan
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Posted: Fri May 19, 2017 3:22 am Post subject: Re: Another VW Engineering Blunder... |
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You can find Bilstien shock with Heim ends on them, _________________ 'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works" |
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Busstom Samba Member
Joined: November 23, 2014 Posts: 3841 Location: San Jose, CA
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Posted: Fri May 19, 2017 11:41 am Post subject: Re: Another VW Engineering Blunder... |
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lil-jinx wrote: |
If the shock or the bearing housing is worn out of round,that means the shock bolt was not tight at some point and allowed the shock to pound on the bolt.If all was tight there would be no movement,therefor no wear.
I went and took a look at my shock mount bolts,the top bolt is also on an angle that looks the same as the bottom bolt,when the shock is installed at ride height it is angled in at the top which explains the bolts been on an angle.I did not measure the angles to see if they are the same,I assume they are,as you said it makes no sense to have them different. |
Hmmm, I’ll have to look closer (again) at my upper bolts. I’m pretty sure that they’re parallel (or nearly) to the ground. If I’m understanding you correctly, I think you’re suggesting that your setup looks like the red shock absorber on the left (in the image below). If that’s true, then the whole situation is even more wonky than previously thought. Every type 1 and 2 VW I have/had, up to model years ’68, have roughly-parallel bolt planes top and bottom, on all four shocks (especially the front ends, those are dead-nuts parallel). A little variation is understandable and acceptable, but the target goal is parallelism - top and bottom - to start with. Of course - in any application, if the whole shock is tilted, then the mounts and bolts tilt with it, right? But that's not what I'm talking about here.
I’m not trying to beat the crap out of this topic, I’m just trying to understand why at some point, VW decided that it was a good idea to angle the lower mounting bosses on the IRS bearing housings of these later Buses. Perhaps it made it easier to get tools on the bolts to change shocks while they were on the lift...maybe it sped up manufacturing somehow…I dunno.
Mike, I hear you...I don't care so much about this Westy, but I do run Afco heim shocks on my '64 Bus.
Thanks for your responses.
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TDCTDI Samba Advocatus Diaboli
Joined: August 31, 2013 Posts: 12848 Location: North Carolina
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Posted: Fri May 19, 2017 11:57 am Post subject: Re: Another VW Engineering Blunder... |
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VW over-designed almost everything on these vehicles, I seriously doubt that something like that was a blunder. It's probably designed that way so that in the event of the suspension suddenly coming unloaded, the shock doesn't slip off the end of the bolt should the bushing fail since they didn't use a washer larger than the ID of the shock eyelet. _________________ Everybody born before 1975 has a story, good, bad, or indifferent, about a VW.
GOFUNDYOURSELF, quit asking everyone to do it for you!
An air cooled VW will make you a hoarder.
Do something, anything, to your project every day, and you will eventually complete it. |
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sodbuster Samba Member
Joined: August 08, 2004 Posts: 1084 Location: wherever my baywindow takes me.
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Posted: Fri May 19, 2017 12:32 pm Post subject: Re: Another VW Engineering Blunder... |
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Since every baywindow bus is like this it begs the question. Has this effected the running or handling of any bus anytime anywhere ever? I'm betting the answer to this is a resounding no! If that is the case then I'd say this topic is about a non issue. And if that is the case, I for one refuse to fall into this trap of annul compulsiveness.
just sayin'. |
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Spike0180 Samba Member
Joined: June 06, 2015 Posts: 2269 Location: Detroit, Michigan
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Posted: Fri May 19, 2017 7:15 pm Post subject: Re: Another VW Engineering Blunder... |
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Are the two bolts in the same vertical plane? If not the lower would need that angle for the shock to meet up with the top bolt. That would be my guess.
Edit: just looked at some pictures. I think the shock is angled in a little. It would give better geometry than straight up and down. _________________ Brutis Patches Izabich: 1970 VW Transporter - 1776cc DP
Current State: Projects never truly end...
Location: Grosse Pointe, Michigan
Other cars: 2003 F150, 2003 Jetta GLI vr6-6sp
Sambastic: adj; the quality of being nit picky, elitist, expecting everyone to do things the way they believe is best with no regard to situation, "sambastic" |
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timvw7476 Samba Member
Joined: June 03, 2013 Posts: 2200 Location: seattle
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Posted: Fri May 19, 2017 8:32 pm Post subject: Re: Another VW Engineering Blunder... |
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If you put a gun to my head, I would guesstimate they did it to keep the
shock's frequency from working in unison with the rear torsion bars
& generating freakish harmonics when you hit nasty washboard pavement.
Only a guess, they aren't on the same plane with that bottom bolt where it is.
+ my bus handles washboard like it does not care, so.... |
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Abscate Samba Member
Joined: October 05, 2014 Posts: 22641 Location: NYC/Upstate/ROW
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Posted: Sat May 20, 2017 2:36 am Post subject: Re: Another VW Engineering Blunder... |
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If the bushing life exceeds the shock body life, then bushing wear isn't an issue. I'm sure that this is true if torqued correctly, with good parts. _________________ .ssS! |
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lil-jinx Samba Member
Joined: August 14, 2013 Posts: 1109 Location: New Brunswick,Canada
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Posted: Sat May 20, 2017 5:58 am Post subject: Re: Another VW Engineering Blunder... |
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https://www.thesamba.com/vw/gallery/pix/1644511.jpg
Yes,The bolts look like those on the left,but the shock is tilted to the left,which bring the mount eyes more in line with the bolts.
The shock angle would change as it expands and compresses,I would thing at ideal ride height that the bolts would be in proper alienment with the shocks.
Sodbuster--this may be a non-issue,but then again it may un- cover a problem with the Op's shock mounts,either way it is a few vw enthusiasts discussing vws,is that not what this forum is all about? _________________ https://www.thesamba.com/vw/forum/viewtopic.php?t=620186
https://www.thesamba.com/vw/forum/viewtopic.php?t=668799
1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy
1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes. |
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Busstom Samba Member
Joined: November 23, 2014 Posts: 3841 Location: San Jose, CA
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Posted: Sat May 20, 2017 8:19 am Post subject: Re: Another VW Engineering Blunder... |
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lil-jinx wrote: |
<snip> ... it is a few vw enthusiasts discussing vws,is that not what this forum is all about? |
^this...
Thanks again for the feedback, guys.
Edit: added pic.
This is what I'm talking about...minor issue? Yes. Anyway, this is how my lower sleeves have egg'd a bit and opened the seam in the sleeves, and the wear pattern on the rubber bushings show the bias to the bottom. I know, they look a little toasty, but since they're "fitted" and feel really smooth still, they should be good to roll.
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lil-jinx Samba Member
Joined: August 14, 2013 Posts: 1109 Location: New Brunswick,Canada
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mikedjames Samba Member
Joined: July 02, 2012 Posts: 2736 Location: Hamble, Hampshire, UK
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Posted: Sat May 20, 2017 12:58 pm Post subject: Re: Another VW Engineering Blunder... |
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Just a thought.. What if the split in the rubber started on one side first and that breakage induced the twisting that damaged the metal. That initial split makes the remainoing solid part of the bush misaligned with the thrust from the shock absorber.
Then it starts chewing metal, especually if the nut and bolt were not fully tightened.
Replace the bushes and the bolts.
Look at it this way instead. Your bus has a problem, several million busses did not have a problem.
Your rubber bushing is split. It has just halved in strength because when you pull on the rubber it just opens up instead of stretching. _________________ Ancient vehicles and vessels
1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.
1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy |
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